docs: def build_services(did, service_descriptors):
          """
          Build a list of services.
  
          :param did: DID, str
          :param service_descriptors: List of tuples of length 2. The first item must be one of
          ServiceTypes
          and the second item is a dict of parameters and values required by the service
          :return: List of Services
          """
          services = []
          sa_def_key = ServiceAgreement.SERVICE_DEFINITION_ID
          for i, service_desc in enumerate(service_descriptors):
              service = ServiceFactory.build_service(service_desc, did)
              # set serviceDefinitionId for each service
              service.update_value(sa_def_key, str(i))
              services.append(service)
  
          return services